Desperate weather near desert (4-5)
I believe the answer is:
last-ditch
'desperate' is the definition.
(I've seen this before)
'weather near desert' is the wordplay.
'weather' becomes 'last' (I've seen this in another clue).
'near' is a charade indicator (letters next to each other).
'desert' becomes 'ditch' (ditching is a kind of deserting).
'last'+'ditch'='LAST-DITCH'
(Other definitions for last-ditch that I've seen before include "Of an attempt or stand, final and desperate" , "Denoting final attempt (to do something)" , "Final recourse" , "Stitch lad up in final defence" , "Eleventh-hour" .)